Checkout page don't show the correct currency defined

Hello,
I’m using a plugin to change the currency of just one product (tour).
The plugin is “Booster for WooCommerce Tools” and the module that does this function is “Currency per Product”.
The plugin displays the currency defined on the tour page. However, on the checkout page the default currency is displayed again.
I think it’s because the theme has its own checkout page that is not allowing for the correct plugin compatibility.
You can reproduce the error through this tour ( https://travelwp.estacaofloresta.com.br/roteiros/punta-cana/)and proceed to the checkout page
The tour currency is US$ and the default currency is R$. In this case the checkout page must show only $ and not R$.
Can you help me solve this problem?
thanks